EPROM IC Distributor in China

UNIFORTUNE EPROM stores and retails data even the power is switch off. It enables data retrieval when the power is turned on. Our EPROM features a floating gate technology which takes on an electrical charge of the memory cell. EPROM is embedded within a transistor and designed to store charge, the amount of which is used to represent whether the bit of data stored in the memory cell is a ‘1’ 0r ‘0’.

UNIFORTUNE EPROM is suitable for microprocessor system requiring large data or program storage. It is organized as 2 M words of 16bit. The pin-out is compatible with a 32M bit mask ROM. UNIFORTUNE EPROM has a transparent lid which allows the user to expose the chip to ultraviolet light to erase the bit pattern. A new pattern can then be written rapidly to the device by following the programming procedure.

Additionally, UNIFORTUNE EPROM supports to read and write firmware of LCD display and TV motherboard online and out offline. It supports all series of 25 and 26 SPI FLASH memory, support identify the chips part number automatically and the capacity is up to 256Mbit. The EPROM IC programming the internal high-speed MCU control to upgrade your PC software to complete the feature upgrades, more compatible models using USB interface. It eliminates the need for bulky power adapter, easier to use.

UNIFORTUNE deals in all kinds of IC brands world-wide. The electronic components manufacturers’ engineers’ team carefully choose material and technology for manufacturing all EPROM IC. With the accurate quotation, excellent credit, reasonable price, reliable quality, fast delivery, authentic service, we have won the praise of majority of customers.

For OEM or custom EPROM IC, the engineers help in design concept and CAD drawing while helping in material specification and size of the product. Avail now the best EPROM IC. We warmly welcome people from all over the world to contact and cooperate with us.

EPROM IC: The Ultimate FAQ Guide

There are many types of memory ICs.

And today, I am going to answer all questions you may have about EPROM IC.

So, if you are a newbie, or an expert who wants to learn more, then this is a-must-read guide for you.

Let’s dive right in:

What is an EPROM IC?

EPROM is a contraction of Erasable Programmable Read-Only Memory.

An EPROM IC is a non-volatile memory chip that allows you to erase and modify its contents. The erasure process is facilitated with the use of Ultra Violet light.

EPROM IC

Where do you use an EPROM IC?

You find EPROM ICs are utilized in the following instances:

• EPROM ICs are used as bootstrap loaders to store instructions for a computer’s basic input/output system.
• You will find EPROM ICs used in embedded systems such as microcontrollers to store their program data.
• EPROM ICs were utilized by old generation computers for memory storage.
• Video game makers use EPROM ICs to store game data and code for video games.

EPROM in electronic system

What Memory defines an EPROM IC?

An EPROM IC stores data in the form of non-volatile memory.

Non-volatile memory is storage that retains saved data when power is cut off. This means that, once data is stored, an interruption of power supply will not lead to loss of the saved data.

This property allows non-volatile memory chips to be used as secondary storage for computer systems. It also allows for larger densities.

The other type of memory is called volatile memory.

Memory chips that store volatile memory lack the ability to retain saved data upon interruption of power supply.

Random Access Memory chips for example store volatile memory. As such, volatile storage is characterized by low densities.

Volatile storage is used as cache memory and primary memory for many computers.

This is because it is easily and quickly accessed allowing the processor to carry out multiple functions simultaneously.

What are the components of EPROM ICs?

An EPROM IC constitutes an array of floating gate transistors.

Floating gate transistor

The basic storage unit of an EPROM IC is a single field-effect resistor. The field-effect resistor is composed of a channel with contact ends for drain and source.

A layer of oxide with insulating properties covers the channel with another layer above it of a gas electrode.

The gas electrode layer has conductive properties.

Above the gas electrode is a control gate electrode that is also layered with an insulating oxide.

How does an EPROM IC Work?

An EPROM IC consists of an array of floating gate transistors. The transistors are arranged in such a way as to form rows and columns.

At each intersection of a column and row, you will find two transistors separated by the channel with an oxide layer.

The transistors at the intersection are designated floating and control gates respectively.

The Fowler-Nordheim tunneling technique is used to alter the position of electrons in the floating gate.

A charge is applied that causes electrons to get excited pushing their way into the channel. This causes them to acquire a negative charge.

These electrons block the floating gate transistor with a cell sensor checking the charge level at the floating gate.

For an electron flow level exceeding half the charge percentage, the binary logic “1” is designated.

For an electron flow level less than half the charge percentage, the binary logic “0” is designated.

Data stored is determined by the absence or presence of electrons in the channel between the two gates.

To write an EPROM IC chip, you need to erase it.

A high energy level capable of tunneling through the negatively charged electrons blocking access to the floating gate is needed.

An ultraviolet light source is best placed to execute the process.

How do you Read an EPROM IC?

EPROM Circuit

To be able to read an EPROM IC, you need to understand the following features related to it.

A single location in an EPROM IC stores only a single byte of data. Note that a byte of data is equal to eight bits.

Each location has a unique address and to access a single byte of data you need to identify its address.

You find pins designated A0 to A14 which provide access to the addresses with the information you want to read.

An EPROM IC has eight pins designated Q0 to Q7which assist you in reading the byte.

To read, you need to put down the address location on the address lines (those pins designated “A”).

You identify the address by writing it on the address line in binary form. Each “0” means the application of 0V whereas each “1” requires application of a voltage of 5V.

The EPROM IC responds by placing the byte from the desired location address on the data line.

The other pins referred to as control pins are of significant use too.

• The Chip Enable (CE) pin acts as a switch. When you apply 0V, it puts the EPROM IC on. Apply a voltage of +5V, the EPROM IC is off.
• At the Output Enable (OE) pin, 0v enables the output while +5V disables it.
• The programming voltage is applied to the Vpp pin. The voltage amount depends on the EPROM IC type.
• The Vcc pin is the source of the positive supply voltage of +5V.
• The Vss pin acts as the common ground at 0V.

With these in mind, you can surmise the read operation as follows.

• Enable the chip by applying 0V at the Chip Enable (CE) pin.
• Enable output by applying 0V at the Output Enable (OE) pin.
• Specify the address by writing its binary form on the address lines (pins designated A0…A14).
• On signal achieving stability, read the byte on the data lines (pins designated Q0…Q7)
• Repeat the process for other address locations.

Is an EPROM IC Read Only?

No, it is not.

You find that you can read and write onto an EPROM IC chip.

This is because an EPROM IC chip is erasable and programmable. This allows for the modification of data in an EPROM chip.

An EPROM IC chip is erased by the use of ultraviolet light.

The UV light source is directed onto an EPROM IC chip through a quartz window on its package.

This UV light causes the charge in the memory cell of an EPROM IC chip to scatter.

Since the data in an EPROM IC is stored in the form of a charge, the ionization process results in data loss.

As such, the whole chip is erased. You, therefore, cannot achieve byte-level erasure with an EPROM IC.

EPROM Integrated Circuit

How do you write an EPROM IC?

Writing an EPROM IC involves the same protocols for the read procedure save for the instructions.

To write an EPROM IC, you execute the following steps.

• Enable the chip by ensuring the Chip Enable (CE) is at 0v.
• Disable the output by supplying a voltage of +5V at the Output Enable (OE).
• Then apply the voltage for programming on the Vpp pin.
• At the Vcc pin, the supply voltage of a little more than +5V such as +6.3V to enhance the write.
• Identify the unique location address in which to store the byte (the pins designated A)
• Write the byte on the specific data line (Q pins)
• Upon attainment of signal stability provide a quick turn voltage on the Output Enable (OE). You do this by supplying 0v for a fraction of a second then quickly switching to +5V.
• Execute the same procedure for the other addresses selected.

How do you Erase Data from an EPROM chip?

You erase data on an EPROM IC by using an ultraviolet light source.

An EPROM IC is packed in a plastic casing with a quartz crystal window.

This window allows the die to be exposed to UV light. The EPROM IC chip should be very close to the ultraviolet light source.

On exposure, the UV light photons induce the ionization process within the silicon oxide. This, in turn, causes the charge stored on the chip’s floating gate to vaporize.

Data stored in an EPROM IC memory cell is in the form of a charge. The loss of charge, therefore, results in the loss of the data stored therein.

This is because the whole memory of the array is unshielded from the radiation.

You should be careful not to over-erase the EPROM IC by exposing it to the UV light far too long.

This causes the floating gates in the EPROM IC to be overcharged. Consequently, they are no longer able to hold any electrons.

How many times can you Erase data from an EPROM ICs?

An EPROM IC allows several hundred erase-write cycles.

You should note that the erasure process in an EPROM IC wholly depletes the stored data. This is unlike an EEEPOM IC chip where erasure is at the byte level.

How long does it take to erase an EPROM IC?

The duration of the erasure process in an EPROM IC is subject to the source of UV light that you use.

Appropriately sized UV lamps will take a couple of minutes to erase an entire EPROM IC chip.

Using sunlight will take you at least three weeks to get through the erasure process. Relegating erasure responsibility to indoor fluorescent will take years to get the job done.

What is OTP (One Time Programmable) EPROM IC?

A One Time Programmable EPROM IC is one that once programmed is unalterable by not supporting erasure.

This is because they are assembled in a windowless plastic package making it impossible to carry out the erasure process.

The OTP EPROM IC came about due to the high cost of making the quartz crystal window. Eliminating the window, therefore, brought about cost advantage.

What is the difference between ROM, PROM, and EPROM?

The differences between these memory types are:

       i. ROM

Read-Only Memory is a memory type where you can read but not write on it. It is a non-volatile memory type and thus retains saved data in the absence of power.

The information written onto and stored on a read-only memory upon manufacture is permanent.

You find the application of read-only memory in the storage of startup instructions for computers and select electronic appliances.

      ii. PROM

Programmable Read-Only Memory is another non-volatile memory storage chip. It allows you to amend its contents only once.

Thereafter, the information on an altered PROM is permanent restricting further modification.

While a ROM chip has data written into it during manufacture, PROM chips are programmed after manufacture.

You use an electric device called a PROM programmer to write onto the PROM chips.

A PROM chip is bought with a reading of “1” for all the bits. A PROM chip is programmed by the use of a current source as opposed to a voltage source.

To program, you burn a fuse bit causing a change in its read to a “0”.

You can find PROM chips are in microcontrollers, gaming consoles, radio frequency identification tags, and high-definition multimedia interfaces.

    iii. EPROM

An Erasable and Programmable Read-Only Memory is also a non-volatile memory storage type.

You can erase an EPROM IC and reprogram it. You program an EPROM IC by trapping an electrical charge in a gate region that is insulated.

With no path for leakage, the charge can be retained for a long time, over a decade.

You erase the data on an EPROM IC by exposing it to UV rays. By directing the UV light through a quartz window, you cause the charge to scatter.

You have to detach the EPROM chip from the device’s main circuit board to carry out the erasure process.

How does an EPROM IC compare with an EEPROM IC Chip?

An EPROM IC and an EEPROM IC are similar in several ways as you will see.

• Both the EPROM IC and EEPROM IC are erasable allowing you to change the information stored on them.
• Besides, both the EPROM and EEPROM ICs allow you to reprogram them after erasure.
• You find both the EPROM IC and EEPROM IC employ transistors as their cell storage locations.
• Additionally, both memory chips are utilized as related hardware for external programming.

Even so, you will realize several differences between the EPROM IC and the EEPROM IC.

• While both are erasable, the EPROM IC utilizes UV light in the process while the EEPROM IC utilizes an electric signal.
• They have different physical characteristics with the EPROM IC identifiable by the quartz crystal window atop the package. The EEPROM IC is completely enclosed in a windowless plastic package.
• You use a hot electron injection technique to program an EPROM IC. You use the tunneling effect method to program an EEPROM IC.
• To erase an EPROM IC, you have to detach it from the device’s circuit board. For an EEPROM IC, you can carry out the erasure process without having to detach the chip from the mainboard.
• It takes you a couple of minutes to erase an EPROM chip. An EEPROM IC will take you fractions of a second to complete the erasure process.
• An EPROM IC erasure process results in the erasure of the whole memory array. This is because the erasure process exposes the whole memory cell to UV light. This results in the dissipation of all the charges. An EEPROM IC allows erasure at the byte level. This allows you to only erase parts retaining the integrity of other data bytes.

What are some of the Advantages of using an EPROM IC?

You will realize the following advantages in employing the EPROM IC:

• The EPROM IC is cost-effective.
• You can reprogram an EPROM IC.
• An EPROM IC can store and retain data in the absence of power.
• An EPROM IC is convenient when testing and debugging.

What are some of the Limitations of an EPROM IC?

You encounter the following limitations in using an EPROM IC:

• EPROM ICs have high static power consumption.
• You can’t erase a single byte in an EPROM IC.
• The transistors in EPROM ICs have high resistance.
• You cannot electrically erase an EPROM IC but with the use of UV light.
• You need to remove an EPROM IC from the device’s mainboard to carry out erasure.
• The erasure process is time-consuming in comparison to alternative memory ICs like the EEPROM IC.
• You can only achieve several hundred erase-write cycles with an EPROM IC.

What is a Quartz Window in an EPROM IC Package?

EPROM Memory Cells

The quartz window is a distinguishing feature of the EPROM IC package.

The quartz crystal window is made from amorphous silica which gives it the property of having a high working temperature.

It also provides better transmission of ultraviolet light.

The quartz window is useful in allowing erasure of the EPROM IC. It is through the quartz window that the UV light is directed to erase the EPROM IC chip.

What is an EPROM programmer?

An EPROM programmer is an electronic device that is used to organize written software onto an EPROM IC.

You insert an EPROM IC into a socket on the EPROM programmer. By applying signals through the connecting pins, you can transfer data from the programmer into the EPROM IC.

How can you Test EPROM ICs?

You test an EPROM IC by taking its Vcc reading at low, nominal and high levels.

When an EPROM IC has lost sufficient charge, it can indicate a correct reading at low Vcc.

However, testing it at nominal Vcc will result in a dissimilar reading.

You will be able to monitor the program margin when you check its value at a high Vcc.

Are EPROM ICs still used?

EPROM ICs presently find limited use having been replaced by EEPROM ICs.

EEPROM ICs are electrically erasable programmable read-only memory chips.

As you can tell from their name, they improve on the regular EPROM IC by allowing electrical erasure of the chip.

The electrical erasure process is faster than the use of UV light in erasing EPROM ICs.

An EEPROM IC will ideally take a fraction of a second to carry out an erase procedure. Alternately, you will take several minutes to erase an EPROM IC.

Also, EEPROM ICs carry out erasure at the byte level. This way, you can only delete a particular byte of data rather than the whole chip.

The erasure process in an EPROM ICs deletes the whole memory cell.

The whole-cell in an EPROM IC is deleted because the whole chip is exposed to the ultraviolet light.

This causes all the charges stored in the floating gate transistors to dissipate. Since data in the cells is stored in the form of a charge, all of the data stored is lost.

What are the Features of the EPROM IC?

You find the following features on an EPROM IC.

• An operating supply voltage of +5V during operations for a read.
• A short access time of 45 ns (nanoseconds).
• Use of complementary MOS technology that is highly reliable.
• Low power consumption with an active current rating of 30mA and standby current rating of 100 µA.
• A programming voltage requirement of 12.75V ± 0.25V at the Vpp and 6.0 ±0.25V at the Vcc.
• Faster programming times of about 6 seconds.
• An organization of 256K x 8-bit.
• Two, line controls, the Output Enable (OE) and Chip Enable (CE).
• Temperature range of between 0º to 70º C.
• Lead-free Dual Inline Package with a 32-pin.

How much does EPROM IC Cost?

You find that EPROM ICs cost much lower than EEPROM ICs. Prices for EPROM ICs vary depending on the intended use.

Ultimately, the average price of an EPROM chip amounts to less than a dollar apiece. Purchasing of EPROM ICs in large quantities further drives down their prices.

Why Import EPROM IC from China?

EPROM Integrated Circuit(IC)

You will identify the following perks from acquiring EPROM IC chips from China.

• China made EPROM IC chips are low-priced.
• EPROM chips in China are highly reliable with the use of Complementary Metal-Oxide Semiconductors (CMOS).
• Chinese made EPROM ICs have low power consumption needs.
• You derive faster programming times with EPROM ICs made in China.
• EPROM ICs acquired from China have short access times, typically in nanoseconds.
• With increased environmental awareness, China made EPROM ICs are assembled in lead-free packages.

As I finish this EPROM IC FAQ guide, maybe you could be having more questions.

Don’t hesitate to talk to UNIFORTUNE team. We are here to help you learn and import high performance memory chips from China.